Pick-up device detecting changes of the volume of mucous membranes in the mouth

ABSTRACT

A pick-up device for detecting changes in the volume of mucous membranes in the mouth consisting of a plate shaped electrode provided with an insulating coating. The electrode is supported by a holder adapted to be clamped between teeth of the upper and lower jaw so that one side of said electrode faces the investigated tissue. The other side is electrically screened. The insulated coating of the pick-up electrode facing the investigated tissue is provided with at least two extension for securing a correct predetermined distance from said tissue.

United States Patent Figar [451 Mar. 21, 1972 [721 ephan. eztliraevsa seflekie 1 Assignw sa ke A S?Q?EIEWY?FL PEE EQE Czechoslovakia 221 Filed: No. 10, 1969 [2]] Appl. No.: 875,277

[52] U.S. Cl. ..128/2.1 E, 128/2.05 V, 128/409, 128/DIG. 4

[51] Int. Cl. ..A61b 5/05 [58] Field ofSearch ..128/2.1,205 V,DIG. 4,413,

[56] References Cited UNITED STATES PATENTS 1,697,325 ll1929 Perlman ..128/416 X 1,975,518 10/1934 Rose ..128/416 2,078,391 4/1937 Last ..128/413 X 2,184,511 12/1939 Bagno et a1 ...l28/2.l X 2,583,853 l/1952 Kazdin 1 ..128/404 2,882,904 4/1959 Rasmussen ...128/418 3,398,740 8/1968 Figar ..l28/2 3,405,715 10/1968 Hagfors ..128/4l8 FOREIGN PATENTS OR APPLICATIONS 371,553 1/1907 France ..l23/416 1,360,384 3/1964 France ..128/4I8 687,916 2/1940 Germany ..128/2.l

626,407 7/ 1949 Great Britain. ....128/413 44,569 5/1961 Poland 123/21 OTHER PUBLICATIONS Groom, D. et al., Amer. Journ. of Medical Electronics, Oct.- Dec., 1964, pp- 26l 265 Primary Examiner-Richard A. Gaudet Assistant Examiner-Kyle L. Howell Attorney-Richard Low [57] ABSTRACT A pick-up device for detecting changes in the volume of mucous membranes in the mouth consisting of a plate shaped electrode provided with an insulating coating The electrode is supported by a holder adapted to be clamped between teeth of the upper and lower jaw so that one side of said electrode faces the investigated tissue. The other side is electrically screened. The insulated coating of the pick-up electrode facing the investigated tissue is provided with at least two extension for securing a correct predetermined distance from said tissue.

7 Claims, 4 Drawing Figures PICK-UP DEVICE DETECTING CHANGES OF THE VOLUME F MUCOUS MEMBRANES IN THE MOUTH BACKGROUND OF THE INVENTION This invention relates to a pickup device for detecting changes in the volume of mucous membranes in the mouth, for instance of the alveolar and gingival membrane. The pickup device of the present invention is based on the electrocapacitive principle requiring no direct contact of the applied electrode with the investigated tissue. An electrocapacitive plethysmographic pickup device for investigation in the mouth has as yet not been proposed. Measurements of changes of the volume of the mucous membrane in the mouth has a theoretical and practical significance, as said changes indicate changes in the blood circulation and thus also of the functioning of blood vessels of the mucous membrane. Such measurements are rather difficult with the known devices due to complex conditions of the mouth. The generally used mechanical plethysmographs are not practical due to the necessity of sealing the investigated tissue in the mechanical plethysmographic pickup device. But even if this difficulty could be overcome, other drawbacks of this method remain, namely in the production of pressure and heat on the investigated tissue.

SUMMARY OF THE INVENTION It is an object to this invention to provide a pickup device capable of detecting changes of the volume of mucous membranes in the mouth without the inconveniences connected with the application of mechanical plethysmographic pickup devices. It is another object of this invention to provide a pickup device for the detection of changes of the volume of mucous membranes in the mouth which would operate quickly and without inconvenience to the investigated person.

It is a still further object of this invention to provide a pickup device which could be easily adapted to different conditions when investigating different tissues in the mouth. The pickup device according to this invention is provided with a pickup electrode having the shape of a plate, made of a wire gauze connected by a screened cable with the live potential of a device for detection of changes of the electric capacity. The shape of said plate is adjusted to the part of the surface of the mouth which has to be investigated plethysmographically. The plate is insulated by a layer of insulating material provided with at least two extensions on the surface facing the investigated tissue. The extensions provide a certain distance between the pickup electrode and the investigated area. The surface distant from the investigated tissue is screened by means of a screening electrode extending beyond the edge of the pickup electrode and connected conductively with the zero potential already aforementioned device for detection of changes of the electrical capacity. The whole pickup device is fixed on a holder of a shape adapted to be clamped between teeth of the upper and lower jaw. The device is secured by a clamp retracting the lip or the cheek from the pickup device, for instance by means of a wire sling fixed under the chin or on some other place of the face or head.

DESCRIPTION OF DRAWINGS An exemplary embodiment of the pickup device according to this invention is illustrated in the accompanying drawings where FIG. 1 is a vertical sectional view of the pickup device in the mouth of the investigated person,

FIG. 2 is a top view of the applied device with parts thereof in section,

FIG. 3 a view of the internal face of the pickup electrode,

FIG. 4 a top view of the pickup electrode.

DESCRIPTION OF PREFERRED EMBODIMENT The pickup electrode 1 is a plate of electrically conductive material, preferably of a wire gauze which is flexible and pliant, covered by a coating 3 of insulating material. It is provided with at least two extensions 15 on the side facing the tissue to be investigated. The projections 15 insure that a certain distance from said tissue has, for instance, from the gum 14 is obtained. A screening electrode 2 is fixed on the whole surface of the other side of the pickup electrode 1. The pickup electrode 1 is connected by shielded cable 4 with a device for detection and/or registration of changes of the electrical capacity, for instance with the live potential of an oscillator connected with a discriminator. The screening electrode 2 is grounded as by being connected with the zero potential of the detecting device, while the pickup electrode 1 is also connected with the live potential of the same oscillator. The screening electrode 2 is simultaneously connected by the conductor 17 with the shield 16 of the cable 4. The screening electrode 2 has edges which extend beyond the edges of the pickup electrode 1 and is provided with two extensions 18 by which it is fixed to a holder 5 of the pickup device. The holder 5 is made from suitable material and shaped so as to be adapted for squeezing between the teeth 13 of the upper and lower jaw 12. At least one of the extensions 15 of the insulating coating 3 serves as the support of a unipolar or bipolar exciting electrode 6, connected via a supply cable 7 with an electric stimulator. Two small hoses terminating in a pouch 8 made of heat conductive material are fixed on and pass through the holder 5.

In order to secure the correct operation of the pickup device, a clamp 10 for retracting the lip 11 or the cheek is provided, having for instance the shape of a wire sling fixed under the chin or on some other place of the face or head. This clamp enables the insertion of the pickup electrode into the mouth and permits its location close to the surface of the mucous membrane of the mouth, for instance of the gum, whereby the distance of the pickup electrode from the investigated surface and its position with respect to said surface is fixedly secured. As the holder 5 can be clamped between teeth of the upper and lower jaw 12 a stable relative position of the pickup device with respect to the surrounding area is secured. The screening electrode 2 determines the extent of the measured area, leaving a part of the pickup electrode not screened. The investigated person is electrically grounded or connected with the zero potential of the device for detection of changes of the electrical capacity. As for example, with the zero potential of the oscillator. The live potential of the detector is connected to the pickup electrode 1 by an electrical conductor. The clamp 10 for retracting the lip 11 prevents any mechanical pressure on the pickup device, which could cause an unwanted movement of the pickup device. The mouth and the pickup electrode form a capacitor, the first plate of which is the electrode 1, the second plate of which is the surface tissue of the mouth and the dielectric is the ambient air therebetween. While the pickup device maintains a fixed spaced position with respect to the measured area, for instance of the gum, any change of volume of the investigated mucous membrane shows as a change of thickness of the air gap between the surface of the investigated tissue and of the pickup electrode 1 and thus also as a change of the electrical capacity between the pickup electrode 1, and the surface of the investigated tissue. These changes of the electrical capacity are transformed into changes of electric voltage by some known device adapted for this purpose, for instance by a discriminator, and can be furthermore. registered by some recording device, for instance by a polygraph.

Measurements of changes of volume of the mucous membrane of the mouth by using the described pickup device are performed by first introducing the whole pickup device into the mouth, whereby the holder 5 of the pickup device is clamped between teeth 13 of the upper and lower jaw 12, and the pickup electrode 1 is maintained at a certain distance from the investigated area of the mucous membrane. The extensions 15 of the insulating coating 3 of the pickup electrode 1 secured thereby the required distance of the pickup electrode 1 from the mucous membrane. One of said extensions 15 is provided with an exciting electrode 6, by means of which electric stimula causing reactions of the blood vessels of the mucous membrane can be generated.

The pouch 8 of a heat conductive material is pressed against a place of the mucous membrane in the neighborhood of the investigated area, whereby water of different temperatures passes through said pouch 8 via the supply and discharge hose 9. Thus cold and hot stimula can be produced causing reactions of the blood vessels of the mucous membrane. The clamp 10 fixed below the chin or on some other place of the face or head prevents possible mechanical interferences from the lip l l or cheek.

I claim 1. A pickup device for sensing changes in the volume of mucous tissue membranes in the mouth comprising a holder adapted to be inserted within the mouth a first electrode comprising a flexible conductive plate adapted to conform to the shape of the portion of the mouth to be sensed,

said first electrode being coated with an insulating material,

at least two insulated members projecting from one side of said first electrode adapted to engage said mouth to space said first electrode a fixed distance from the tissue thereof,

a second electrode secured exteriorly of said insulated coating on the other side of said first electrode for screening said first electrode,

said second electrode being secured to said holder,

means for connecting said first electrode to a live potential and said second electrode to ground,

said first electrode and said mouth forming a capacitor, one

plate of which is the first electrode, the other plate of which is the tissue of the mouth to be sensed and dielectric of which is the ambient air therebetween, and

means electrically connected to said first electrode for sensing changes in capacitance.

2. A pickup device as set forth in claim 1 wherein said first electrode is made of wire gauze.

3. A pickup device as set forth in claim I wherein at least one of the extensions of the insulating coating of the pickup electrode supports an exciting electrode connected to an electric stimulating device.

4. A pickup device as set forth in claim 1 including a pouch made of heat conductive material and supported by said holder, said pouch including hoses for the supply and discharge of a liquid thereto.

5. The device according to claim 1 wherein said extending members and said coating are formed of integral insulating material.

6. The device according to claim 1 wherein the edges of said second electrode extend beyond the edges of said first electrode.

7. The device according to claim 1 wherein said means for connecting the live potential to the first electrode comprises a shielded cable. 

1. A pickup device for sensing changes in the volume of mucous tissue membranes in the mouth comprising a holder adapted to be inserted within the mouth a first electrode comprising a flexible conductive plate adapted to conform to the shape of the portion of the mouth to be sensed, said first electrode being coated with an insulating material, at least two insulated members projecting from one side of said first electrode adapted to engage said mouth to space said first electrode a fixed distance from the tissue thereof, a second electrode secured exteriorly of said insulated coating on the other side of said first electrode for screening said first electrode, said second electrode being secured to said holder, means for connecting said first electrode to a live potential and said second electrode to ground, said first electrode and said mouth forming a capacitor, one plate of which is the first electrode, the other plate of which is the tissue of the mouth to be sensed and dielectric of which is the ambient air therebetween, and means electrically connected to said first electrode for sensing changes in capacitance.
 2. A pickup device as set forth in claim 1 wherein said first electrode is made of wire gauze.
 3. A pickup device as set forth in claim 1 wherein at least one of the extensions of the insulating coating of the pickup electrode supports an exciting electrode connected to an electric stimulating device.
 4. A pickup device as set forth in claim 1 including a pouch made of heat conductive material and supported by said holder, said pouch including hoses for the supply and discharge of a liquid thereto.
 5. The device according to claim 1 wherein said extendinG members and said coating are formed of integral insulating material.
 6. The device according to claim 1 wherein the edges of said second electrode extend beyond the edges of said first electrode.
 7. The device according to claim 1 wherein said means for connecting the live potential to the first electrode comprises a shielded cable. 